We have jointly considered the question whether clause 2 of the Income Tax Bill 1943, by providing that the Governor-General may not proclaim the Act before the National Welfare Fund Act 1943 comes into operation, contravenes the rule laid down in section 55 of the Constitution that ‘laws imposing taxation shall deal only with the imposition of taxation’. We are all of opinion that it does not. This view accords with the opinion which two of our number (the Solicitor-General and Mr Castieau) expressed on 11th March,(1) when a request from the Senate for the omission of the words in question was received by the House of Representatives.

In setting out the question referred to us we have deliberately refrained from the use of the word ‘tacking’, which is a term with a long Parliamentary history but with no fixed meaning. Strictly employed, it denotes the inclusion in a money Bill of an extraneous clause to secure its passage through an Upper House which cannot amend money Bills. More loosely used, it is said to include any Parliamentary procedure as a result of which the adoption of a money Bill is linked with the fate of any other measure. Upon this, we observe only that the financial proposals of Governments may be, and indeed commonly are, linked with other measures without evoking any thought of protest. Decisions as to the order in which business is brought before the Houses, for example, or declarations of Government policy, may effectively link the Government’s financial proposals with its measures of general policy. But in the Commonwealth the reciprocal rights and duties of the two Houses are not left to be determined by historical analogies or by general views of constitutional propriety. They have been prescribed with some precision by the Constitution. It does not refer to ‘tacking’. It does not forbid the linking by any and every means of a money Bill with other measures. It imposes by section 55 two specific prohibitions as to the form of laws imposing taxation, and the only question is whether the Income Tax Bill is in a form which will involve a contravention of either of them.

In point of form, the relevant words in clause 2 of the Income Tax Bill 1943 merely fix a date before which the Act may not be proclaimed to commence. In substance, however, they may also be regarded as expressing a condition upon which, and upon which alone, the taxes prescribed by the Act are to be imposed. The substance of the condition is that if it becomes necessary to raise money to establish a National Welfare Fund as well as for other purposes, tax is to be imposed at the rates prescribed; if not, then not. We think that the formulation of this condition is an integral part of the process of imposing the obligation to pay the tax.

We do not think it necessarily follows from the view we have expressed that any condition whatever could validly be inserted in a taxing Act. We do not suppose, for example, that on this view a law whose operation was expressly made conditional on the happening of some clearly irrelevant event, such as the passing of another Act regarding naturalisation, or divorce, or the service and execution of process, could properly be described as a law that ‘deals only with the imposition of taxation’. But in such a case the other Bill would have no relation to the purposes for which money was to be raised, or the amount of money needed. In the present instance the condition can reasonably be regarded as incidental to the determination of the amounts to be raised. Such matter as this is proper for inclusion in a law imposing taxation: see Buchanan v. Commonwealth (1913) 16 C.L.R. 315, 328, per Barton J.

References in a taxing Bill to another measure which is before the Parliament at the same time and which forms an integral part of the taxing plan are by no means uncommon and have evoked no comment or protest in either House. The invariable mode of such a reference is to describe the other measure as an ‘Act’, although technically it may be still in the form of a Bill. One illustration out of many that may be given is the Dairy Produce Export Charges Act 1924 which contained provisions that were dependent for their operation on the passing of the Dairy Produce Export Control Act 1924. In Osborne v. Commonwealth (12 C.L.R. 321) the validity of such a reference was upheld by the High Court although the taxing Act received the Royal Assent prior to the Assessment Act which was incorporated with it.

The considerations we have put forward above seem to us decisive of the present question. We are inclined to the view, however, that good reasons can be given for taking even higher ground. Clause 2 of the Bill undoubtedly refers to a matter other than the imposition of taxation. But, for the purposes of section 55 of the Constitution, to ‘deal with’ a matter seems to mean something more than merely to ‘refer to’ it. It seems to mean to make some provision of law with regard to it. The difference can perhaps be most easily illustrated from the second paragraph of the section, which prescribes inter alia that laws imposing duties of customs ‘shall deal with duties of customs only’. Suppose for example that a customs tariff fixed certain duties, but with the condition that on the imposition of additional excise duties on the goods the duties of customs should be increased by x per cent. We think that such a provision would be properly held to ‘deal with duties of customs only’. Yet it would certainly refer to the passing of another measure, and it would also plainly link the two measures together politically. Similarly we think the reference now under discussion, to the National Welfare Fund Act, would not turn clause 2 into a law that deals with some matter other than the imposition of taxation.

In a matter that has not hitherto been the subject of express judicial decision, we recognise that any opinion must have something of a tentative character. We know that strongly differing views are held in the present instance. We have tested our own view, however, by assuming its opposite, and supposing that the condition does deal with a matter other than the imposition of taxation. If it did, then section 55 would nullify it: ‘any provision therein dealing with any other matter shall be of no effect’. In that event, the Government could ignore the condition. If, therefore, the National Welfare Fund Bill did not become law, and the view of the Senate is correct, the Income Tax Act could nevertheless be proclaimed at any time by the Government. We could not possibly advise the Government, if events turned out as we have imagined, that the reference to the National Welfare Fund Act is a mere nullity. Yet if it does deal with a matter other than the imposition of taxation it must be.

In conclusion we wish to draw attention to the difference between the manner in which the Constitution deals with taxation and appropriation Bills respectively. The Senate cannot amend either: section 53, paragraph 2. Then section 54 enacts that ‘the proposed law which appropriates revenue or moneys for the ordinary annual services of the Government shall deal only with such appropriation’. There is no sanction. No Court could prevent or restrain a breach. The whole matter is left for political action. If the Senate does not uphold its privileges, there is no other remedy. But the position is different in the case of taxation measures. The Constitution does not deal with taxing Bills, or ‘proposed laws’ as it calls them, at all. It deals only with measures after enactment. Section 55 deals with ‘laws imposing taxation’. The matter has then gone beyond political action, and the Constitution imposes on the particular provisions that offend against its requirements the sanction of nullity. While therefore the Senate is undoubtedly within its rights in requesting the amendment of any tax Bill which it thinks contravenes section 55, it is not under any constitutional duty to do so. The question is dealt with, as a matter of law, by the Constitution, thus obviating the necessity for political action.(2)